Mattchen U.S. Pat. No. 4,583,531 discloses a hand held, pulsating jet, lavage usable for surgical purposes. A pressure air powered, reciprocating motor drives a reciprocating irrigant liquid pump to produce a pulsed irrigant liquid stream from the front of the barrel of the gun-shaped lavage. The motor is connected to a continuous source of pressure air.
However, the Mattchen motor and pump are separate and separable units, the pump unit being disposable and the motor unit being not. More particularly, in Mattchen the forward portion of the barrel hinges open for removal and replacement of the pump unit, the irrigant liquid supply tube and the pulsating irrigant liquid outlet tube. The top front portion of the barrel is hinged at the bottom front of the barrel, so as to tilt forwardly and allow upward removal of the mentioned pump unit and liquid supply and outlet tubes. The remainder of the apparatus, which is to be reused, comprises the motor unit and a relatively complex pressure air control valving system which is trigger operated to modulate the flow of pressure air to the motor and thereby control the pulsed irrigant liquid output flow indirectly. The construction complexity of the handpiece as a whole would appear to make it economically impossible to market as a disposable handpiece, and indeed the teaching of Mattchen on the point is clear. Accordingly, separate sterilizations of the pump unit, with its liquid hoses, on the one hand, and on the other hand the remainder of the handpiece, as well as the need to assemble and disassemble the two appear to add further to the cost and extra time required to use this system on an on-going basis.
Smith U.S. Pat. No. 4,278,078 (assigned to the assignee of the present invention) is pressure air powered and does provide a pulsing irrigant liquid outflow. However, the Smith unit is not in the handy form of a pistol, and is not a disposable tool. Further, irrigant liquid is supplied to the tool by gravity from an elevated storage container and passes through the tool in a resiliently compressible tube. A hammer reciprocated by an air motor repetitively pinches and unpinches the resilient tube to pulse the flow of irrigant liquid therethrough. The irrigant liquid pulses tend to have gradual, rather than sharp, start and stop characteristics. The apparatus does not "pump" from a liquid store located vertically below it.
Atkinson U.S. Pat. No. 4,655,197 discloses a handpiece providing a pulsating liquid flow for lavage use. However, pulsed irrigant liquid is applied to the handpiece from a remote pulsing source, in the form of a self-standing console. Liquid pulses may thus tend to become less sharp and well defined before they reach the handpiece.
Kovach U.S. Pat. No. 3,561,433 discloses a hand-held dental cleaning and massaging device. However, the Kovach device is in the form of a wand whose base includes both a small water reservoir providing the sole source of liquid and a CO.sub.2 cartridge as the sole pressure gas supply. A trigger button shifts the valve core to permit pressurized water to flow from the outlet end of the wand. An undisclosed type of liquid pulsing device, of extremely compact size, joins the water outlet tube to the base portion of the wand. The only specific suggestion of a pulsing device given is that it may be a fluidic multivibrator or oscillator. The water supply is necessarily very small in volume and the pressure of the pressure gas is very high (as high as 900 PSI). The reliability and repeatability of the pulsing unit is unknown. The structure is relatively complex for its limited capability. Disposability appears neither to be taught nor economically feasible.
The objects and purposes of this invention include provision of a pulsed surgical irrigation handpiece and a self-contained motor/pump unit therefor, which apparatus is intended to be disposable after use and not to be reusable, which is producible as a sealed handpiece unit, which has a streamlined exterior free of tubes except at the base of the handle and at the forward end of the barrel, which is capable of incorporating and controlling suction as well as pulsed irrigant liquid, which has a self-contained motor/pump cartridge capable of producing sharp irrigant liquid pulses, which includes a "pop" pressure gas exhaust feature contributing to a rapid irrigant liquid pulse fall time, and which locates the motor/pump cartridge in the handle of the pistol-shaped handpiece to distribute weight between the handle and barrel of the handpiece and thereby provide a well-balanced hand tool.
Other object and purposes of the invention will be apparent to persons acquainted with apparatus of this general type upon reading the following description and inspecting the accompanying drawings.